Patent US3886465A successfully refreshed from Google Patents.
US3886465A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Class b push-pull output stage of an amplifier
Assignee: Telefunken Electronic GmbH
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Filing: 1973-10-16
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Granted: 1975-05-27
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Expires: 1993-10-16
Abstract
Abstract A class B push-pull amplifier has an output stage formed of two transistors having their connector-emitter paths connected in a series path across a direct voltage source. The transistors are controlled by a driver transistor which is supplied via an additional transistor having a resistance connected in series with its emitter. A further transistor having its base-emitter path connected across this resistance is so arranged and controlled that variations in the voltage of the voltage source have little or no effect on the current through the series path linking the transistors of the output stage.
Inventors
- 👤 Johann Mattfeld
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:39
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/30; H03F3/3083; H03F3/3086; H03F3/3091; H03F1/00; H03F1/30; H03F1/307
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
199 words
In an amplifier having a class B push-pull transistor output stage, a driver stage including a driver transistor for triggering said output stage and means for maintaining the collector closed circuit current of the transistors of said output stage independent of temperature fluctuations, and means, including an external load resistance connected in series with the emitter-collector path of said driver transistor across the supply voltage terminals for the amplifier, for maintaining the collector closed circuit current of the transistors of said output stage independent of supply voltage fluctuations, the improvement wherein: said amplifier further includes a signal input transistor having its output connected to the base of said driver transistor and arranged for triggering said driver transistor; said external load resistance comprises the collector-emitter path of an additional transistor provided with an emitter resistor and forming part of a contstant current source; and said constant current source further includes a further transistor having its base emitter path connected in parallel with said emitter resistor, and its emitter collector path connected into the collector path of said transistor arranged for triggering the said driver transistor, the collector of said further transistor being connected to the base of said additional transistor.
Claim 2
Dependent Claim
199 words
In an amplifier having a class B push-pull transistor output stage, a driver stage including a driver transistor for triggering said output stage and means for maintaining the collector closed circuit current of the transistors of said output stage independent of temperature fluctuations, and means, including an external load resistance connected in series with the emitter-collector path of said driver transistor across the supply voltage terminals for the amplifier, for maintaining the collector closed circuit current of the transistors of said output stage independent of supply voltage fluctuations, the improvement wherein: said amplifier further includes a signal input transistor having its output connected to the base of said driver transistor and arranged for triggering said driver transistor; said external load resistance comprises the collector-emitter path of an additional transistor provided with an emitter resistor and forming part of a contstant current source; and said constant current source further includes a further transistor having its base emitter path connected in parallel with said emitter resistor, and its emitter collector path connected into the collector path of said transistor arranged for triggering the said driver transistor, the collector of said further transistor being connected to the base of said additional transistor.
Claim 3
Dependent Claim
40 words
An amplifier having a class B push-pull output stage according to claim 1, wherein the said additional and further transistors belonging to the constant current source are complementary transistors to the said transistor arranged for triggering the said driver transistor.
Claim 4
Dependent Claim
51 words
An amplifier having a class B push-pull output stage according to claim 1, wherein the said transistor arranged for triggering the said driver transistor is provided in its emitter feed line with a voltage divider the mean tapping of which is connected to the base electrode of the said driver transistor.
Claim 5
Dependent Claim
33 words
An amplifier having a class B push-pull output stage according to claim 1, wherein the said transistor arranged for triggering the said driver transistor is a pre-amplifying transistor connected as an emitter follower.
Claim 6
Dependent Claim
30 words
An amplifier having a class B push-pull output stage according to claim 1, wherein the components of the circuit are accommodated in a common semiconductor body in an integrated form.
Claim 7
Dependent Claim
202 words
A class B push-pull amplifier, comprising an output stage which includes a first output transistor and a second output transistor having their collectors connected in a series path between first and second supply terminals, a direct voltage source across said terminals, a driver stage comprising a driver transistor and arranged for controlling the first and second output transistors, and means, including an additional transistor having its emitter collector path and an emitter resistor therefore connected in series with the collector-emitter path of the driver transistor between said supply terminals, for controlling the current through the driver transistor to substantially offset the effect of variations in the voltage of the direct voltage source on the current in the said series path, said means further including a further transistor having its emitter-base path connected in parallel with said emitter resistor and its collector connected to the base of said additional transistor, a signal input transistor having its emitter-collector path connected in series with the emitter-collector path of said further transistor, and a voltage divider connected between the emitter of said signal input transiStor and one of said supply terminals, the tap of said voltage divider being connected to the base of said driver transistor.
Claim 8
Dependent Claim
202 words
A class B push-pull amplifier, comprising an output stage which includes a first output transistor and a second output transistor having their collectors connected in a series path between first and second supply terminals, a direct voltage source across said terminals, a driver stage comprising a driver transistor and arranged for controlling the first and second output transistors, and means, including an additional transistor having its emitter collector path and an emitter resistor therefore connected in series with the collector-emitter path of the driver transistor between said supply terminals, for controlling the current through the driver transistor to substantially offset the effect of variations in the voltage of the direct voltage source on the current in the said series path, said means further including a further transistor having its emitter-base path connected in parallel with said emitter resistor and its collector connected to the base of said additional transistor, a signal input transistor having its emitter-collector path connected in series with the emitter-collector path of said further transistor, and a voltage divider connected between the emitter of said signal input transiStor and one of said supply terminals, the tap of said voltage divider being connected to the base of said driver transistor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |